1 /*
2 * Copyright 2019 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty5.util.internal;
17
18 import io.netty5.util.concurrent.EventExecutor;
19 import io.netty5.util.concurrent.FastThreadLocal;
20
21 import java.util.Objects;
22 import java.util.concurrent.Executor;
23 import java.util.concurrent.ThreadFactory;
24
25 /**
26 * Allow to retrieve the {@link EventExecutor} for the calling {@link Thread}.
27 */
28 public final class ThreadExecutorMap {
29
30 private static final FastThreadLocal<EventExecutor> mappings = new FastThreadLocal<>();
31
32 private ThreadExecutorMap() { }
33
34 /**
35 * Returns the current {@link EventExecutor} that uses the {@link Thread}, or {@code null} if none / unknown.
36 */
37 public static EventExecutor currentExecutor() {
38 return mappings.get();
39 }
40
41 /**
42 * Set the current {@link EventExecutor} that is used by the {@link Thread}.
43 */
44 private static void setCurrentEventExecutor(EventExecutor executor) {
45 mappings.set(executor);
46 }
47
48 /**
49 * Decorate the given {@link Executor} and ensure {@link #currentExecutor()} will return {@code eventExecutor}
50 * when called from within the {@link Runnable} during execution.
51 */
52 public static Executor apply(final Executor executor, final EventExecutor eventExecutor) {
53 Objects.requireNonNull(executor, "executor");
54 Objects.requireNonNull(eventExecutor, "eventExecutor");
55 return command -> executor.execute(apply(command, eventExecutor));
56 }
57
58 /**
59 * Decorate the given {@link Runnable} and ensure {@link #currentExecutor()} will return {@code eventExecutor}
60 * when called from within the {@link Runnable} during execution.
61 */
62 public static Runnable apply(final Runnable command, final EventExecutor eventExecutor) {
63 Objects.requireNonNull(command, "command");
64 Objects.requireNonNull(eventExecutor, "eventExecutor");
65 return () -> {
66 setCurrentEventExecutor(eventExecutor);
67 try {
68 command.run();
69 } finally {
70 setCurrentEventExecutor(null);
71 }
72 };
73 }
74
75 /**
76 * Decorate the given {@link ThreadFactory} and ensure {@link #currentExecutor()} will return {@code eventExecutor}
77 * when called from within the {@link Runnable} during execution.
78 */
79 public static ThreadFactory apply(final ThreadFactory threadFactory, final EventExecutor eventExecutor) {
80 Objects.requireNonNull(threadFactory, "command");
81 Objects.requireNonNull(eventExecutor, "eventExecutor");
82 return r -> threadFactory.newThread(apply(r, eventExecutor));
83 }
84 }